In the 1950s, visitors to a brothel atop San Francisco’s Telegraph Hill got more than just a tryst and a view of the bay. Clients were secretly dosed with LSD as CIA agents watched from behind a one-way mirror. Although it sounds like a bad late-night spy movie, Operation Midnight Climax, as it was called, was a very real part of a larger covert project called MKULTRA.

I wrote this for Discover’s “Whatever Happened To…” section in 2008. Read the whole story here.